The present invention relates generally to power seating assists for the infirm, and more specifically, to devices for lifting and tilting in assisting the elderly and disabled in both sitting and alighting from a chair.
Upholstered chairs with lifting/seating assists for the infirm have been commercially available for some time. Those most widely available are marketed as specialty appliances with the lifting mechanism as an integral unit built-in an upholstered chair at the time the chair is manufactured. Consequently, one in need of such an appliance frequently purchases at considerable expense a complete chair and lifting device as a unit. U.S. Pat. Nos. 3,218,102; 4,838,612 and 5,061,010 disclose representative examples of power assisted chairs with the lifting and/or tilting devices as integral units built into the chair.
While such integral power lifting/seating chairs perform quite satisfactorily, a more economic alternative is frequently needed. One such alternative would be the installation or retrofitting of a previously manufactured chair owned by the infirm with a power lifting/seating assist device. However, retrofittable chair lifting and tilting devices have had some significant disadvantages, and consequently, they have had only limited acceptance. For example, U.S. Pat. No. 4,083,599 (Gaffney) discloses a power chair lifting and tilting device with the ability of the device to lift off the floor when fully retracted. This permits an accessory base on the chair having wheels or rocker springs to engage with the floor. However, this chair lifting and tilting device includes a upper frame member which requires a hollow recess in the base of the chair. This additional clearance space is also needed to accommodate a power actuated ram for the lifting device. Hence, the chair lifting and tilting device of U.S. Pat. No. 4,083,599 is not universally adaptable to all chairs, and especially to upholstered chairs having low floor clearances.
Accordingly, it would be highly desirable to have an improved retrofittable chair lifting and tilting device, including one which would be more universally adaptable to most previously manufactured chairs, and can be easily installed without requiring structural modifications to the chair.